Cassiopeia Observatory logo

M87 (jet), M61, and Leo Galaxies Triplet

Posted: 16 April 2015

Strong winds blew most of the day on Wednesday, 15 April 2015, making for a dusty sky. Anticipating that the winds would decrease after sunset, I decided to go to the observatory.

Open: Wednesday, 15 April 2015, 1839 MST
Temperature: 76°F
Session: 808
Conditions: Clear but dusty sky, strong breezes

Due to the strong breezes I delayed uncovering the telescope and powering it on. 1854 MST: sunset. Took this cropped photo of the sun setting behind a distant mountain:


1920 MST: still very breezy with the temperature down to 63°F, but I began preparing the D7200 DSLR for DSO imaging. 1950 MST: still breezy. Closed the dome and returned to the house to wait for breezes to die down or Astronomical Twilight to end.

2010 MST: returned to the observatory. Still breezy but less now.

2014 MST: powered on the 8" LX200-ACF. Dome was still closed but the GPS receiver got a fix. 2017 MST: slewed to Venus and opened the dome. Viewed Venus, 83X, and then viewed Jupiter, 83X. The four Galilean Moons were visible.

Next, slewed to M87 (galaxy), which would be my first DSO imaging target of the night. Viewed M87, 83X, followed by M61 (galaxy), 83X, my 2nd DSO target. 2026 MST: still breezy but decided to try imaging anyway. Slewed to the star Arcturus, mounted the D7200 at prime focus + extension + off-axis guider, and then did a focus test image using the Bahtinov Mask. Slewed back to M87 and began searching for a good guide star. Ten minutes later I found one, but framing of M87 in the viewfinder was not great. Decided to image anyway. I did a 103 second unguided framing test image, followed by guided 10 minute exposures at various ISO settings. During post-processing I discovered that the jet was only visible in the shorter exposure, with the overexposed galaxy hiding it in the longer exposures. Here is the 103 second, ISO 6400, unguided image, cropped from the full-frame image:


The jet from the galaxy's black hole is clearly visible coming out of the galaxy at "10 o'clock". I plan to do more (short) exposures of M87 to try to improve on the jet's visibility.

Slewed to M61 (galaxy). It was visible in the camera viewfinder. Found a faint guide star. This is a guided 5 minute, ISO 6400, exposure, cropped from the full-frame image:


2143 MST: it was still somewhat breezy. Added the focal reducer. Slewed to the Leo Triplet of Galaxies (M65, M66, and NGC3628. Did several framing test exposures to get the three galaxies. Then did a focus test on the star Regulus. Returned to the Leo Triplet and searched for a guide star. Found a good one, but framing was not ideal. Did guided 5 minute, ISO 6400 and ISO 12800 exposures. Galaxy cores were way overexposed in the ISO 12800 image. This is the (cropped) ISO 6400 image:


2251 MST: breezes were stronger again. Slewed to the center of the Virgo Galaxy Cluster. Found a faint guide star. Unfortunately, none of the images were suitable for post-processing to bring out the faint galaxies. The Raw converter for the D7200 DSLR has not yet been released to I am having to use JPEG images at the current time. Will try again when I can easily use and process Raw images.

After imaging the Virgo cluster I slewed to the Coma Galaxy Cluster. Oops, it was at POD "zenith blind spot". Will do on another session after the Raw converter is available.

Removed the camera from the 8" telescope. 2336 MST: viewed Saturn, 83X. Seeing was not good and it was still low in the southeastern sky. Strong breezes were still blowing. I decided to end the session.

Close: Wednesday, 15 April 2015, 2356 MST
Temperature: 50°F

Comments are welcome using Email. If you are on Twitter you can use the button below to tweet this report to your followers. Thanks.

Previous report

Cassiopeia Observatory Home Page

Back to Top

Copyright ©2015 Michael L. Weasner /